6. Tasks

The Tasks section of the administrative GUI is used to configure repetitive tasks:

  • Cron Jobs schedules a command or script to automatically execute at a specified time
  • Init/Shutdown Scripts configures a command or script to automatically execute during system startup or shutdown
  • Rsync Tasks schedules data synchronization to another system
  • S.M.A.R.T. Tests schedules disk tests

Each of these tasks is described in more detail in this section.

Note

By default, Scrubs are run once a month by an automatically-created task. S.M.A.R.T. Tests and Periodic Snapshot Tasks must be set up manually.

6.1. Cron Jobs

cron(8) is a daemon that runs a command or script on a regular schedule as a specified user.

Figure 6.1.1 shows the screen that opens after clicking Tasks → Cron Jobs → Add Cron Job.

_images/cron.png

Fig. 6.1.1 Creating a Cron Job

Table 6.1.1 summarizes the configurable options when creating a cron job.

Table 6.1.1 Cron Job Options
Setting Value Description
User drop-down menu make sure the selected user has permission to run the specified command or script
Command string the full path to the command or script to be run; if it is a script, test it at the command line first to make sure that it works as expected
Short description string optional
Minute slider or minute selections with the slider, the cron job occurs every N minutes; with minute selections, the cron job occurs at the highlighted minutes
Hour slider or hour selections with the slider, the cron job occurs every N hours; with hour selections, the cron job occurs at the highlighted hours
Day of month slider or month selections with the slider, cron job occurs every N days; with day selections, cron job occurs on the highlighted days each month
Month checkboxes cron job occurs on the selected months
Day of week checkboxes cron job occurs on the selected days
Redirect Stdout checkbox disables emailing standard output to the root user account
Redirect Stderr checkbox disables emailing errors to the root user account
Enabled checkbox uncheck disable the cron job without deleting it

Created cron jobs will be listed in View Cron Jobs. Highlight a cron job entry to display buttons to Edit, Delete, or Run Now.

Note

% symbols are automatically escaped and should not be prefixed with backslashes. For example, use date '+%Y-%m-%d' in a cron job to generate a filename based on the date.

6.2. Init/Shutdown Scripts

FreeNAS® provides the ability to schedule commands or scripts to run at system startup or shutdown.

Figure 6.2.1 shows the screen that opens after clicking Tasks → Init/Shutdown Scripts → Add Init/Shutdown Script. Table 6.2.1 summarizes the options.

When scheduling a command, make sure that the command is in the path or give the full path to the command. One way to test the path is to type which command_name. If the command is not found, it is not in your path.

When scheduling a script, make sure that the script is executable and has been fully tested to ensure that it achieves the desired results.

_images/init.png

Fig. 6.2.1 Add an Init/Shutdown Script

Table 6.2.1 Options When Adding an Init/Shutdown Script
Setting Value Description
Type drop-down menu select from Command (for an executable) or Script (for an executable script)
Command string if Command is selected, input the command plus any desired options; if Script is selected, browse to the location of the script
When drop-down menu select when the command/script will run; choices are Pre Init (very early in boot process before filesystems are mounted), Post Init (towards end of boot process before FreeNAS services are started), or Shutdown

6.3. Rsync Tasks

Rsync is a utility that copies specified data from one system to another over a network. Once the initial data is copied, rsync reduces the amount of data sent over the network by sending only the differences between the source and destination files. Rsync can be used for backups, mirroring data on multiple systems, or for copying files between systems.

Rsync is most effective when only a relatively small amount of the data has changed. There are also some limitations when using Rsync with Windows files. For large amounts of data, data that has many changes from the previous copy, or Windows files, Replication Tasks are often the faster and better solution.

Rsync is single-threaded, so gains little from multiple processor cores. To see whether rsync is currently running, use pgrep rsync from the Shell.

Both ends of an rsync connection must be configured:

  • the rsync server: this system pulls (receives) the data. This system is referred to as PULL in the configuration examples.
  • the rsync client: this system pushes (sends) the data. This system is referred to as PUSH in the configuration examples.

FreeNAS® can be configured as either an rsync client or an rsync server. The opposite end of the connection can be another FreeNAS® system or any other system running rsync. In FreeNAS® terminology, an rysnc task defines which data is synchronized between the two systems. To synchronize data between two FreeNAS® systems, create the rsync task on the rsync client.

FreeNAS® supports two modes of rsync operation:

  • rsync module mode: exports a directory tree, and its configured settings, as a symbolic name over an unencrypted connection. This mode requires that at least one module be defined on the rsync server. It can be defined in the FreeNAS® GUI under Services → Rsync → Rsync Modules. In other operating systems, the module is defined in rsyncd.conf(5).
  • rsync over SSH: synchronizes over an encrypted connection. Requires the configuration of SSH user and host public keys.

This section summarizes the options when creating an Rsync Task. It then provides a configuration example between two FreeNAS® systems for each mode of rsync operation.

Note

If there is a firewall between the two systems or if the other system has a built-in firewall, make sure that TCP port 873 is allowed.

Figure 6.3.1 shows the screen that appears after selecting Tasks → Rsync Tasks → Add Rsync Task. Table 6.3.1 summarizes the options that can be configured when creating an rsync task.

_images/rsync1a.png

Fig. 6.3.1 Adding an Rsync Task

Table 6.3.1 Rsync Configuration Options
Setting Value Description
Path browse button browse to the path that to be copied; note that a path length greater than 255 characters will fail
User drop-down menu specified user must have permission to write to the specified directory on the remote system; due to a limitation in FreeBSD, the user name cannot contain spaces or exceed 17 characters
Remote Host string IP address or hostname of the remote system that will store the copy; use the format username@remote_host if the username differs on the remote host
Remote SSH Port integer only available in Rsync over SSH mode; allows specifying an SSH port other than the default of 22
Rsync mode drop-down menu choices are Rsync module or Rsync over SSH
Remote Module Name string only appears when using Rsync module mode, at least one module must be defined in rsyncd.conf(5) of rsync server or in the Rsync Modules of another system
Remote Path string only appears when using Rsync over SSH mode, enter the existing path on the remote host to sync with (e.g. /mnt/volume); note that maximum path length is 255 characters
Validate Remote Path checkbox if the Remote Path does not yet exist, check this box to have it automatically created
Direction drop-down menu choices are Push or Pull; default is to push to a remote host
Short Description string optional
Minute slider or minute selections if use the slider, sync occurs every N minutes; if use minute selections, sync occurs at the highlighted minutes
Hour slider or hour selections if use the slider, sync occurs every N hours; if use hour selections, sync occurs at the highlighted hours
Day of month slider or day selections if use the slider, sync occurs every N days; if use day selections, sync occurs on the highlighted days
Month checkboxes task occurs on the selected months
Day of week checkboxes task occurs on the selected days of the week
Recursive checkbox if checked, copy will include all subdirectories of the specified volume
Times checkbox preserve modification times of files
Compress checkbox recommended on slow connections as reduces size of data to be transmitted
Archive checkbox equivalent to -rlptgoD (recursive, copy symlinks as symlinks, preserve permissions, preserve modification times, preserve group, preserve owner (super-user only), and preserve device files (super-user only) and special files)
Delete checkbox delete files in destination directory that do not exist in sending directory
Quiet checkbox suppresses informational messages from the remote server
Preserve permissions checkbox preserves original file permissions; useful if User is set to root
Preserve extended attributes checkbox both systems must support extended attributes
Delay Updates checkbox when checked, the temporary file from each updated file is saved to a holding directory until the end of the transfer, when all transferred files are renamed into place
Extra options string rsync(1) options not covered by the GUI; if the * character is used, it must be escaped with a backslash (\*.txt) or used inside single quotes ('*.txt')
Enabled checkbox uncheck to disable the rsync task without deleting it; note that when the Rsync service is OFF, the rsync task will continue to look for the server unless this checkbox is unchecked

If the rysnc server requires password authentication, input –password-file=/PATHTO/FILENAME in the Extra options box, replacing /PATHTO/FILENAME with the appropriate path to the file containing the value of the password.

Created rsync tasks will be listed in View Rsync Tasks. Highlight the entry for an rsync task to display buttons for Edit, Delete, or Run Now.

6.3.1. Rsync Module Mode

This configuration example configures rsync module mode between the two following FreeNAS® systems:

  • 192.168.2.2 has existing data in /mnt/local/images. It will be the rsync client, meaning that an rsync task needs to be defined. It will be referred to as PUSH.
  • 192.168.2.6 has an existing volume named /mnt/remote. It will be the rsync server, meaning that it will receive the contents of /mnt/local/images. An rsync module needs to be defined on this system and the rsyncd service needs to be started. It will be referred to as PULL.

On PUSH, an rsync task is defined in Tasks → Rsync Tasks → Add Rsync Task. In this example:

  • the Path points to /usr/local/images, the directory to be copied
  • the Remote Host points to 192.168.2.6, the IP address of the rsync server
  • the Rsync Mode is Rsync module
  • the Remote Module Name is backups; this will need to be defined on the rsync server
  • the Direction is Push
  • the rsync is scheduled to occur every 15 minutes
  • the User is set to root so it has permission to write anywhere
  • the Preserve Permissions checkbox is checked so that the original permissions are not overwritten by the root user

On PULL, an rsync module is defined in Services → Rsync Modules → Add Rsync Module. In this example:

  • the Module Name is backups; this needs to match the setting on the rsync client
  • the Path is /mnt/remote; a directory called images will be created to hold the contents of /usr/local/images
  • the User is set to root so it has permission to write anywhere
  • Hosts allow is set to 192.168.2.2, the IP address of the rsync client

Descriptions of the configurable options can be found in Rsync Modules.

To finish the configuration, start the rsync service on PULL in Services → Control Services. If the rsync is successful, the contents of /mnt/local/images/ will be mirrored to /mnt/remote/images/.

6.3.2. Rsync over SSH Mode

SSH replication mode does not require the creation of an rsync module or for the rsync service to be running on the rsync server. It does require SSH to be configured before creating the rsync task:

  • a public/private key pair for the rsync user account (typically root) must be generated on PUSH and the public key copied to the same user account on PULL
  • to mitigate the risk of man-in-the-middle attacks, the public host key of PULL must be copied to PUSH
  • the SSH service must be running on PULL

To create the public/private key pair for the rsync user account, open Shell on PUSH and run ssh-keygen. This example generates an RSA type public/private key pair for the root user. When creating the key pair, do not enter the passphrase as the key is meant to be used for an automated task.

ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
f5:b0:06:d1:33:e4:95:cf:04:aa:bb:6e:a4:b7:2b:df root@freenas.local
The key's randomart image is:
+--[ RSA 2048]----+
|        .o. oo   |
|         o+o. .  |
|       . =o +    |
|        + +   o  |
|       S o .     |
|       .o        |
|      o.         |
|    o oo         |
|     **oE        |
|-----------------|
|                 |
|-----------------|

FreeNAS® supports RSA keys for SSH. When creating the key, use -t rsa to specify this type of key.

Note

If a different user account is used for the rsync task, use the su - command after mounting the filesystem but before generating the key. For example, if the rsync task is configured to use the user1 user account, use this command to become that user:

su - user1

Next, view and copy the contents of the generated public key:

more .ssh/id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC1lBEXRgw1W8y8k+lXPlVR3xsmVSjtsoyIzV/PlQPo
SrWotUQzqILq0SmUpViAAv4Ik3T8NtxXyohKmFNbBczU6tEsVGHo/2BLjvKiSHRPHc/1DX9hofcFti4h
dcD7Y5mvU3MAEeDClt02/xoi5xS/RLxgP0R5dNrakw958Yn001sJS9VMf528fknUmasti00qmDDcp/kO
xT+S6DFNDBy6IYQN4heqmhTPRXqPhXqcD1G+rWr/nZK4H8Ckzy+l9RaEXMRuTyQgqJB/rsRcmJX5fApd
DmNfwrRSxLjDvUzfywnjFHlKk/+TQIT1gg1QQaj21PJD9pnDVF0AiJrWyWnR root@freenas.local

Go to PULL and paste (or append) the copied key into the SSH Public Key field of Account → Users → View Users → root → Modify User, or the username of the specified rsync user account. The paste for the above example is shown in Figure 6.3.2. When pasting the key, ensure that it is pasted as one long line and, if necessary, remove any extra spaces representing line breaks.

_images/rsync2.png

Fig. 6.3.2 Pasting the User’s SSH Public Key

While on PULL, verify that the SSH service is running in Services → Control Services and start it if it is not.

Next, copy the host key of PULL using Shell on PUSH. The following command copies the RSA host key of the PULL server used in our previous example. Be sure to include the double bracket >> to prevent overwriting any existing entries in the known_hosts file:

ssh-keyscan -t rsa 192.168.2.6 >> /root/.ssh/known_hosts

Note

If PUSH is a Linux system, use this command to copy the RSA key to the Linux system:

cat ~/.ssh/id_rsa.pub | ssh user@192.168.2.6 'cat >> .ssh/authorized_keys'

The rsync task can now be created on PUSH. To configure rsync SSH mode using the systems in our previous example, the configuration is as follows:

  • the Path points to /mnt/local/images, the directory to be copied
  • the Remote Host points to 192.168.2.6, the IP address of the rsync server
  • the Rsync Mode is Rsync over SSH
  • the rsync is scheduled to occur every 15 minutes
  • the User is set to root so it has permission to write anywhere; the public key for this user must be generated on PUSH and copied to PULL
  • the Preserve Permissions checkbox is checked so that the original permissions are not overwritten by the root user

Save the rsync task and the rsync will automatically occur according to the schedule. In this example, the contents of /mnt/local/images/ will automatically appear in /mnt/remote/images/ after 15 minutes. If the content does not appear, use Shell on PULL to read /var/log/messages. If the message indicates a n (newline character) in the key, remove the space in the pasted key–it will be after the character that appears just before the n in the error message.

6.4. S.M.A.R.T. Tests

S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) is a monitoring system for computer hard disk drives to detect and report on various indicators of reliability. When a failure is anticipated by S.M.A.R.T., the drive should be replaced. Most modern ATA, IDE, and SCSI-3 hard drives support S.M.A.R.T.–refer to the drive documentation for confirmation.

Figure 6.4.1 shows the configuration screen that appears after selecting Tasks → S.M.A.R.T. Tests → Add S.M.A.R.T. Test. Tests are listed under View S.M.A.R.T. Tests. After creating tests, check the configuration in Services → S.M.A.R.T., then click the slider to ON for the S.M.A.R.T. service in Services → Control Services. The S.M.A.R.T. service will not start if there are no volumes.

Note

To prevent problems, do not enable the S.M.A.R.T. service if the disks are controlled by a RAID controller. It is the job of the controller to monitor S.M.A.R.T. and mark drives as Predictive Failure when they trip.

_images/smart1.png

Fig. 6.4.1 Adding a S.M.A.R.T. Test

Table 6.4.1 summarizes the configurable options when creating a S.M.A.R.T. test.

Table 6.4.1 S.M.A.R.T. Test Options
Setting Value Description
Disks list highlight disks to monitor
Type drop-down menu select type of test to run; see smartctl(8) for a description of each type of test (note that some test types will degrade performance or take disks offline; do not schedule S.M.A.R.T. tests at the same time as a scrub or during a resilver operation)
Short description string optional
Hour slider or hour selections if use the slider, test occurs every N hours; if use hour selections, test occurs at the highlighted hours
Day of month slider or day selections if use the slider, test occurs every N days; if use day selections, test occurs on the highlighted days
Month checkboxes select the months for the test to occur
Day of week checkboxes select the days of the week for the test to occur

An example configuration is to schedule a Short Self-Test once a week and a Long Self-Test once a month. These tests should not have a performance impact, as the disks prioritize normal I/O over the tests. If a disk fails a test, even if the overall status is Passed, start to think about replacing that disk.

Warning

Some S.M.A.R.T. tests cause heavy disk activity and can drastically reduce disk performance. Do not schedule S.M.A.R.T. tests to run at the same time as scrub or resilver operations or during other periods of intense disk activity.

Which tests will run and when can be verified by typing smartd -q showtests within Shell.

The results of a test can be checked from Shell by specifying the name of the drive. For example, to see the results for disk ada0, type:

smartctl -l selftest /dev/ada0

If an email address is entered in the Email to report field of Services → S.M.A.R.T., the system will send email to that address when a test fails.